Candy Crush is a huge hit, but what’s next for its developer?

Mobile game developer King is bringing in a lot of money from its hyper-addictive free-to-play game Candy Crush Saga. The mobile game is the top grossing app in the Apple App store and Google Play, and, according to app analysis website ThinkGaming, processing almost $65ok a day from its estimated user base of 6.6 million people.

But after four weeks at the top, Candy Crush Saga will likely fizzle out as fast as it shot up. According to The Atlantic, Dots, the last game du jour, ceded its place as the top app after roughly a month, and that’s the standard time for apps to cycle in and out of the spotlight. Candy Crush Saga could be old news well before the fall, just around the time the company is rumored to be planning an IPO.

Although King has been around for a decade and has released hundreds of games online, none has taken off like Candy Crush Saga. The company currently has two other mobile games in rotation — Pet Rescue Saga and Bubble Witch Saga — neither of which is poised to capture the coveted top-grossing spot.

So what’s next for King? Here are some takeaways from the experiences of other game publishers that have produced hits, acquired other properties, and built full-fledged companies.

1. Buy the games, not the developers

After developing a major hit, many companies feel the pressure to replicate that blockbuster success by creating a new game. That’s much trickier than it seems, though. When you have cash like King does, it could be smarter to buy an already-developed game.

Buying an unknown game with the potential to be a hit from a small developer can be a better way to go. Angry Birds devleoper Rovio has had some early success distributing already-made games under its new Rovio Stars program. Though Rovio Stars is still in its infancy, one of its first two games, Ice Breaker: A Viking Voyage! received a warm reception from critics, while its second, Tiny Thief, debuted in the Top 10 paid games on iTunes.

2. Choose the right merchandise

King has already dipped its toe into merchandising Candy Crush Saga with branded socks – but there’s lots more it could do on that front, and Rovio may be a model to copy. The Finnish mobile gaming giant has, of course, been very successful with the Angry Birds franchise, and a large portion of its revenue comes from clever merchandising strategies.

In April, the company announced €152.2 million ($195 million) in revenue for 2012, and 45% of that came from licensing the Angry Birds franchise and merchandising, particularly targeting kids. Those Angry Birds lunch boxes, board games and fruit snacks added €55.5 million ($71 million) in profit for Rovio.

On the other hand, Zynga struck a deal to bring Draw Something to television network CBS. Despite early interest, the pilot disappeared. Not all licensed partnerships work out, so sticking to a reliable demographic (like children, who love merchandise) tends to work better.

3. Don’t leave Candy Crush Saga behind

The greatest mobile successes — Rovio’s Angry Birds, Zepto Labs’s Cut The Rope, and NimbleBit’s Tiny Tower, to name a few — stay successful by offering a steady stream of updates to their hit games. Whether it’s a new exclusive daily puzzle, added content to extend the life of the game, or just a new skin to match the holidays, older mobile games continue to take up important real estate on smart phones because they keep people coming back for new things.

Disney’s Where’s My Water is nearly two years old, yet it remains a fixture in top free apps (currently holding the sixth position) and has more than 500,000 daily active users, according to ThinkGaming. The game continues to draw people back because of its updates — more levels, secret objectives, and even new stories with alternate gameplay mechanics. By continuing to invest in the original Where’s My Water?, Disney has been able to help drive interest in the series’ newest titles, Where’s My Perry? and Where’s My Mickey?.

Candy Crush Saga already has 350 levels, but that won’t be enough to sustain the game if it were completely abandoned.

4. Build a franchise

This point is perhaps the most obvious — but also the most difficult to execute: build a franchise that continues to delight gamers without being too repetitive. This means keeping the same theme or general gameplay mechanics so casual gamers recognize the brand, but also adding new twists so players don’t get bored.

Developer Imangi Studios had a hit on its hands when its free running game Temple Run shot to the top of both iPhone and Android top grossing charts in January of 2011. The developer’s next game, Temple Run: Brave, was commissioned by Disney in May of 2012 in coordination with the release of the Pixar movie of the same title. It placed the protagonist, Merida, as the endless runner and added a new archery feature.

Other than the (perplexing) inclusion of the word “Saga” in each of its titles, King doesn’t offer a coherent franchise model that builds on any recognizable themes. One idea is building around either the candy world theme or the puzzle mechanics that make Candy Crush so addictive.